14 Charges Discharger, Shield blocker, Caster

The only "must have" is "Voll's protector Holy chainmail to get fast full stacks of power charges.
You can play it with a bad gear!!
The better your gear is, bigger/faster your pulls of mobs will be.

Just keep in mind that you will need ALL of this spell gems:

- Enduring cry (Endurance charges)
- Blood Rage (Frenzy charges)
- Elemental weakness (or critical weakness)
- Discharge

You need a spell to assist dps, do crits, and maybe get mana back! You are free to use ONE this spells:

- Freezing Pulse
- Ice spear
- Arc
- Spark

I recommand this spells too:

- Molten shell
- Tempest shield
- shield charge (or whirling blades, to "move" into the packs)

I use this:

Discharge + Increased area of effect + Culling strike + life leech
(you can add/swicth Increased critical strikes or damage, concentrated effect)

Freezing Pulse + LMP/GMP + Faster projectiles + Mana leech
(you can add/switch Faster casting, Increased critical strikes)

Molten Shell + cast when damage taken + Increased area of effect + concentrated effect
(you can add any elemental damages, or add any kind of elemental AOE spells like "nova")

Elemental weakness + BloodRage + Enduring cry + Blood magic
(cause you don't have enough mana to refresh it. You can add duration and Increased area of effect when you put them on 2 differents items)

Tempest Shield + reduce mana
(you can add any kind of elemental damage too... but remember, you need mana. So it depends on your manapool)

Shield Charge + faster attacks + "spatch".

With this build, you have a loooooot of % block and Hp! So you can easily jump into the fight and wait for hits!

First, you cast Blood rage, then elemental weakness on the pack!
Then, cast some Pulse/arc/spark/ice spear...
You have your full stacks of power charge ? yeaa! So charge in!
Cast Enduring cry ...
....And.... Discharge! Discharge again!!! do it as long as there is standing mobs around! (agree with the fact that one discharge is always enough :)

Because you have 14 charges!!! That means an amazing AoE dps!
Because you have a lot of resists on the tree!
Because you have a lot of block chances!
Because you have a lot of Hp!